Merge r1429559, r1451484 from trunk:

According top my testing 'SSL_SESSION_id2sz' is 4x faster with the use 'ap_bin2hex' instead of
apr_snprintf(..., "%02X" for each character.
Output is the same.

I have left the uppercase conversion, because I'm unsure if it is usefull or not.

SSL_SESSION_id2sz is only used for logging, having it in lowercase shouldn't be an issue.
Submitted by: jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1455223 13f79535-47bb-0310-9956-ffa450edef68